Salt Lake County District Attorney Sim Gill has ruled that a Utah Highway Patrol trooper was legally justified in fatally shooting a Sandy man during a tense encounter on northbound I‑15 on March 27. Investigators say the trooper opened fire after the driver allegedly rammed a patrol vehicle, stopped in the middle of the freeway, and advanced on the officer while holding a knife. The driver, 29‑year‑old Sayed Zeinullah Mousavi, died at the scene.
Gill’s office concluded that the totality of the evidence would likely lead a jury to find the trooper’s use of deadly force met Utah’s legal standard for justification, so prosecutors declined to file criminal charges. The decision followed an independent review and was released Friday, ending the DA’s criminal screening in the case, according to KSL.
How the freeway encounter unfolded
According to the Utah Department of Public Safety, the confrontation began just before 5 p.m. when a Nissan rear‑ended a marked UHP patrol car on northbound I‑15 near 4500 South. The trooper followed the car until it came to an abrupt stop near 3500 South.
Investigators say Mousavi got out of the Nissan holding a knife and moved toward the trooper. The agency reports that the trooper fired his weapon, Mousavi was pronounced dead at the scene, and the trooper was not injured, according to the Department of Public Safety.
Victim's record and DA's account
Court records and prior reporting show Mousavi faced charges in 2024 related to threats and later pleaded guilty to a terrorism‑related offense, receiving a sentence of probation. As outlined in the DA’s summary reported by KSL, an FBI agent visited Mousavi’s home shortly before the I‑15 incident. After that visit, Mousavi swallowed a large amount of Adderall, became increasingly agitated, and vandalized a parked UHP vehicle before driving onto the freeway.
According to that account, Trooper Caden Mower fired 11 times as Mousavi moved toward him with the knife. Mower later told investigators, “I pulled the trigger,” while describing his effort to stop the approaching man. Local coverage of Mousavi’s prior case is available via FOX13.
DA flags mental health and system gaps
Gill called the shooting a tragic outcome and used the case to underscore what he sees as a gap between front‑line law enforcement response and mental‑health resources for people in crisis. He wrote that Mousavi’s family had sought help for him, yet the facts in this case still supported a legal finding that the trooper’s actions were justified, according to the reporting.
The Salt Lake County District Attorney’s Office has issued similar determinations in other recent officer‑involved critical incidents involving UHP troopers, including a separate review that also ended with prosecutors declining to file charges, according to a press notice from the Salt Lake County District Attorney.
Ongoing investigation and what comes next
The trooper remains on administrative leave while the Officer‑Involved Critical Incident protocol team conducts its own independent investigation, separate from the DA’s charging decision.
Officials say that the review will examine body‑worn camera footage and other evidence and could lead to policy or training recommendations. The Department of Public Safety has posted a public release identifying Mousavi and summarizing the initial response on I‑15.
